Fabrication of a Porous Fe–Al Intermetallic Alloy with Ultrahigh Open Porosity

Abstract

Herein, a porous Fe–Al intermetallic material with ultrahigh open porosity is prepared via the multistep sintering process using a Fe–Al–Mn powder mixture as the raw material. The microstructure, phase composition, Mn sublimation, and open porosity of the sintered Fe–Al–Mn compacts are investigated. The compacts sintered at temperatures ≤700 °C are composed of the newly formed Fe/Mn‐based solid solutions, intermetallic phases, and the original elemental particles without the sublimation of Mn. The open porosities of the 650‐ and 700 °C‐sintered compacts are ≈39.83 and ≈47.19 vol%, respectively. After sintering at 1250 °C, Mn is rarely left in the porous body, and a single Fe–Al intermetallic phase with an even chemical composition is generated. The open porosity of the 1250 °C‐sintered compacts is ≈66.67 vol%, superior to other reported porous Fe–Al materials, and its strength is ≈22.5 MPa, which is competitive as well. This work may open a new strategy to design and optimize the high‐quality porous Fe–Al alloy in future.

Effect of Al Content on the Microstructure and Mechanical Properties of the Sintered Fe–Mn–Al Porous Steel

“…The milling was carried out in vacuum. [9,17,34] The milled powder was die pressed under 200 MPa. Two batches of the green compacts (%10 mm in diameter and %2 mm in thickness, %12 mm in diameter and %16 mm in height) were sintered at 640, 700, and 1200 °C for 1 h with the heating rate of 5 °C min À1 , followed by furnace cooling.…”